/* ============================================
   管理后台样式表
   ============================================ */

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --danger: #ef4444;
    --success: #10b981;
    --warning: #f59e0b;
    
    --bg-primary: #f1f5f9;
    --bg-secondary: #ffffff;
    --sidebar-bg: #0f172a;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --border-color: #e2e8f0;
    
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
    
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    
    --transition: all 0.3s ease;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

/* ============================================
   Login Page
   ============================================ */
.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    padding: 20px;
}

.login-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: 48px 40px;
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow-lg);
}

.login-header {
    text-align: center;
    margin-bottom: 32px;
}

.login-header i {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: 16px;
}

.login-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.form-group label i {
    margin-right: 6px;
    width: 16px;
}

.form-group input,
.form-group textarea,
.form-group select {
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-family: var(--font);
    transition: var(--transition);
    background: var(--bg-primary);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99,102,241,0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-hint {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 16px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font);
}

.btn-primary {
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    color: #fff;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(99,102,241,0.3);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

.btn-outline:hover {
    background: rgba(99,102,241,0.08);
}

.btn-danger {
    background: var(--danger);
    color: #fff;
    border-color: transparent;
}

.btn-danger:hover {
    background: #dc2626;
}

.btn-block {
    width: 100%;
}

.btn-large {
    padding: 14px 36px;
    font-size: 1.05rem;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.85rem;
}

.login-hint {
    text-align: center;
    margin-top: 16px;
}

.login-hint p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.login-hint strong {
    color: var(--primary);
}

.login-hint a {
    color: var(--text-light);
    font-size: 0.85rem;
    transition: var(--transition);
}

.login-hint a:hover {
    color: var(--primary);
}

/* ============================================
   Admin Panel
   ============================================ */
.admin-panel {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 260px;
    background: var(--sidebar-bg);
    color: #fff;
    padding: 24px 16px;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    overflow-y: auto;
    z-index: 100;
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 32px;
    padding-bottom: 20px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-header i {
    font-size: 1.8rem;
    color: var(--primary-light);
}

.sidebar-header h2 {
    font-size: 1.2rem;
    font-weight: 700;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.sidebar-nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    color: rgba(255,255,255,0.7);
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
    background: rgba(255,255,255,0.1);
    color: #fff;
}

.sidebar-nav a i {
    width: 20px;
    text-align: center;
}

.logout-link {
    margin-top: auto;
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 16px !important;
    margin-top: 32px;
}

.logout-link:hover {
    color: var(--danger) !important;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: 260px;
    padding: 32px;
    max-width: calc(100vw - 260px);
}

.content-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
}

.content-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

/* Alert */
.alert {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    margin-bottom: 24px;
    font-size: 0.9rem;
}

.alert-success {
    background: #ecfdf5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert-error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.stat-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    color: #fff;
    flex-shrink: 0;
}

.stat-info h3 {
    font-size: 1.8rem;
    font-weight: 800;
    line-height: 1;
    margin-bottom: 4px;
}

.stat-info p {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Dashboard Info */
.dashboard-info {
    margin-top: 24px;
}

.info-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: 28px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.info-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.quick-actions {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.action-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 20px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-primary);
    text-decoration: none;
}

.action-btn:hover {
    border-color: var(--primary-light);
    background: rgba(99,102,241,0.05);
    transform: translateY(-2px);
}

.action-btn i {
    font-size: 1.5rem;
    color: var(--primary);
}

.action-btn span {
    font-size: 0.85rem;
    font-weight: 500;
}

/* Form Sections */
.form-section {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    margin-bottom: 24px;
}

.form-section h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.version-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 20px;
}

.stats-edit-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 20px;
}

/* FAQ Edit Items */
.faq-edit-item {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 16px;
    border: 1px solid var(--border-color);
}

.faq-edit-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.faq-edit-header span {
    font-weight: 600;
    font-size: 0.95rem;
}

/* Form Actions */
.form-actions {
    margin-top: 32px;
    text-align: right;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .quick-actions {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .sidebar {
        width: 200px;
    }
    
    .main-content {
        margin-left: 200px;
        padding: 24px;
        max-width: calc(100vw - 200px);
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .version-grid,
    .stats-edit-grid {
        grid-template-columns: 1fr;
    }
    
    .quick-actions {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .sidebar {
        width: 60px;
        padding: 16px 8px;
    }
    
    .sidebar-header h2,
    .sidebar-nav a span {
        display: none;
    }
    
    .sidebar-nav a {
        justify-content: center;
        padding: 12px;
    }
    
    .sidebar-nav a i {
        margin: 0;
    }
    
    .main-content {
        margin-left: 60px;
        padding: 16px;
        max-width: calc(100vw - 60px);
    }
    
    .content-header {
        flex-direction: column;
        gap: 12px;
        align-items: flex-start;
    }
    
    .form-section {
        padding: 20px;
    }
}